Sofa



FIG. 1 is a front perspective view of a sofa showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a view similar to FIG. 1 but with the parts in a different position; and,

FIG. 5 is a view similar to FIGS 1 and 4 but with the parts in a third position. 

The ornamental design for a sofa, as shown and described. 